Prehistoric Tooth Key To Understanding Dinosaur Interactions

It turns out that the top land and sea dinosaur predators of 200 million years ago interacted more than previously expected. A new study published earlier this month in the German journal Naturwissenschaften, studied a skeleton of a huge land dinosaur with the tooth of a somewhat smaller carnivorous sea dinosaur embedded in it.

Stephanie Drumheller of the University of Tennessee and Michelle Stocker and Sterling Nesbitt, vertebrate paleontologists with the Virginia Tech’s Department of Geosciences, say the their research provides strong evidence the two dominant dino species of the time not only interacted, but did so purposefully.

Prehistoric tooth tells a tale

All of the academic excitement results from a prehistoric tooth. Researchers found the tooth of a semi-aquatic phytosaur lodged in the thigh bone of a larger terrestrial rauisuchid. The tooth was broken off and buried about two inches deep in bone. The wound had, however, healed over, meaning that the rauisuchid, a creature up to 25-30 feet long and more than 4 feet high at the hip, had survived the attack.

Statements from paleontologists

The authors who discovered the prehistoric tooth commented on the significance of their research. “To find a phytosaur tooth in the bone of a rauisuchid is very surprising. These rauisuchids were the largest predators in their environments. You might expect them to be the top predators as well, but here we have evidence of phytosaurs, who were smaller, semi-aquatic animals, potentially targeting and eating these big carnivores,” said study author Drumheller.

“Finding teeth embedded directly in fossil bone is very, very rare,” Drumheller noted, speaking of the bone obtained from the University of California Museum of Paleontology in Berkeley. “This is the first time it’s been identified among phytosaurs, and it gives us a smoking gun for interpreting this set of bite marks.”

“This research will call for us to go back and look at some of the assumptions we’ve had in regard to the Late Triassic ecosystems,” Virgina Tech’s Stocker and paper co-author said. “The aquatic and terrestrial distinctions made were oversimplified, and I think we’ve made a case that the two spheres were intimately connected.”